1. Technical Field
The present invention relates to a display system, a display method, a display terminal, and a non-transitory computer-readable recording medium stored with a display program.
2. Description of Related Art
Information displayed on a display unit of a display terminal such as a tablet and the like can be visually recognized even by, for example, a third party in addition to a user who is a concerned party by looking into the display unit. Therefore, a disadvantage occurs when information which a third party is not allowed to browse, that is, confidential information, is included in the information displayed on the display unit.
With regard to this disadvantage, for example, a technology disclosed in Japanese Unexamined Patent Application Publication No. 2011-10055, by alternately displaying an image of confidential information and other images in a time-division manner, enables only the concerned party equipped with shutter glasses which open and close a shutter by synchronizing at a time-division timing to visually recognize the confidential information.
In addition, for example, as in a technology disclosed in Japanese Unexamined Patent Application Publication No. 2009-204948, by alternately displaying an image of confidential information and an image of an opposite color which cancels the image of confidential information with different polarizations in a time-division manner, only the concerned party equipped with glasses having a polarization switching unit and a polarization filter which synchronize at a time-division timing can visually recognize the confidential information.
However, a disadvantage occurs when information which a third party is allowed to browse, that is, non-confidential information, is present, and the concerned party and the third party want to share the non-confidential information. For example, in the technology described in Japanese Unexamined Patent Application Publication No. 2011-10055 and Japanese Unexamined Patent Application Publication No. 2009-204948, since different images are alternately displayed on a display unit in a time-division manner, if there is a third party who is not equipped with dedicated glasses, the third party views images in which confidential information and non-confidential information are alternately displayed with an afterimage effect, so that the third party has a disadvantage that it is difficult to correctly understand the non-confidential information.